Needle cap assembly for syringe

ABSTRACT

A safety needle cap for a syringe completely covers the hypodermic needle during non-use or between injections. The needle can be easily exposed with a reduced danger of accidental needle-stick injury. The needle cap can be unlocked from the closed position by being rotated, and then slid backwards onto the syringe barrel by a defined travel distance. Several settings, up to the full extension of the needle, are possible. After use, the needle retracted into the cap, once more preventing needle-stick injury.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to medical sharps devices. More specifically theinvention relates to a protective device for a hypodermic needle andsyringe.

2. Description of the Related Art

Accidental sharps contamination, such as needle-stick injuries fromsyringes are all too common. The contamination and infection dangersassociated with such accidents are commonly feared in the medical field.Considerable concerns are associated with the potential for HIV andhepatitis infection, to name just two.

A variety of sharps protectors are described in the art. For instance,U.S. Pat. No. 6,699,223 B2 to Sharp describes a safety syringe in whichthe needle assembly is stored in the syringe barrel after use. U.S. Pat.No. 6,692,470 B2 to Sanpietro describes a syringe assembly with acylindrical shield covering the needle. For the purpose of using thesyringe, the cylindrical shield is pulled back onto the barrel, thusexposing the needle. U.S. Pat. No. 6,616,638 B2 to Peters, III,describes a hypodermic needle cap. Prior to using the syringe, the capis popped off to expose the needle.

While the prior art systems provide a certain amount of safety againstsharps accidents, further improvements are nevertheless desirable.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a protective capfor a sharps device, in particular a needle cap and hypodermic needleassembly for a syringe, which overcomes the above-mentioneddisadvantages of the heretofore-known devices and methods of thisgeneral type and further improve the device with regard to the dangersof needle-stick and similar sharps injuries.

With the foregoing and other objects in view there is provided, inaccordance with a general concept of the invention, a protective capassembly for a sharps device. The assembly comprises:

-   -   a receiver for rigidly holding a sharps element of the sharps        device;    -   a protective cap assembly attached to the receiver and        completely encasing the sharps element in a closed position of        the cap assembly;    -   the receiver being movably disposed in the protective cap        assembly, for movement from the closed position to a functional        position in which the sharps element projects from the        protective cap assembly and the sharps device is in a functional        condition, and from the functional position to the closed        position in which the sharps element is completely retracted in        the protective cap assembly.

In accordance with an added feature of the invention, the protective capassembly includes a clip ring and a protective cap attached to the clipring, and wherein the clip ring is configured to limit a movement of thereceiver in one direction and the cap is configured to limit themovement of the receiver in another direction.

In accordance with a preferred embodiment of the invention, the receiverhas a tab formed on a substantially cylindrical jacket surface thereof,and the protective cap assembly is formed with at least one groove in aninner jacket surface thereof, defining a track within which the tabslides from the locked position to the functional position.

In the preferred embodiment of the invention, sharps device is a syringeand the sharps element is a hypodermic needle.

With the above and other objects in view there is also provided, inaccordance with the invention, a needle cap assembly for a syringehaving a distal end and a hypodermic needle projecting from the distalend. The needle cap assembly comprises:

-   -   a receiver rigidly mountable at the distal end and rigidly        holding the hypodermic needle;    -   a protective cap mounted on the receiver and slidable relative        to the receiver between a closed position in which the        protective cap encases the hypodermic needle completely and a        functional position in which the hypodermic needle projects out        of the protective cap; and    -   mutually cooperating locking devices on the protective cap and        on the receiver for locking the protective cap in the closed        position.

In accordance with an additional feature of the invention, theprotective cap has a tip formed with an opening through which the needleprojects in the functional position, and a membrane covering andsubstantially sealing the opening when the protective cap is in theclosed position and the needle is completely retracted inside the cap.

With the above and other objects in view there is further provided, inaccordance with the invention, a syringe assembly, comprising a syringehaving a plunger and a barrel with a distal end, the needle cap assemblyas described in the foregoing, and a needle held in the receiver of theneedle cap assembly. The needle is mounted, together with the receiverand the needle cap assembly, to the distal end of the barrel.

In accordance with a concomitant feature of the invention, syringe has astandard luer lock and the needle cap assembly and the needle togetherare formed to be mounted on the luer lock.

The safety needle cap and needle assembly provides for a simple and safemeans to prevent needle-stick injuries, particularly in the context ofintramuscular injections. The device is particularly advantageous inthat it is compatible with common preexisting syringe needlecombinations. The product includes safety features that leave verylittle room for error in the high-stress, fast-paced setting typicallyfound in medical treatment facilities.

The novel device is configured to accommodate all regular syringe needlefunctions, including safe disposal. The assembly is at the same time aneedle cap—for needle coverage prior to use and after use—and permitsfull function of the syringe in that the needle may be selectivelyexposed at a variety of positions. That is, the device permitswithdrawing medication, transportation, storage, injection, and evenre-use for multiple injections. The entire procedure is possible withouteven exposing the needle to open sight.

The device is particularly suited for needle gauges in the range from19-25. Other sizes, of course, are possible as well. In a preferredembodiment, the device is configured for use with standard 1, 3, and 5cc syringes. As will be seen from the following description, the lengthof the needle is of little import and the device is usable withfull-length needles, yet can be utilized with several settings thatprovide for the functionality of different length needles.

In a preferred embodiment, the assembly can be packaged as a unit withthe needle inside the cap, and with or without the syringe.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a needle cap for a syringe, it is nevertheless not intended to belimited to the details shown, since various modifications and structuralchanges may be made therein without departing from the spirit of theinvention and within the scope and range of equivalents of the claims.

The construction of the invention, however, together with additionalobjects and advantages thereof will be best understood from thefollowing description of the specific embodiment when read in connectionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the needle cap assembly according to theinvention in combination with a syringe shown in a closed position;

FIG. 2 is a perspective view of the needle cap assembly and the syringeshown in a half position;

FIG. 3 is a perspective view of the needle cap assembly and the syringeshown with the needle in a fully extended position;

FIG. 4 is a top perspective, exploded view of the entire assemblyaccording to the invention;

FIG. 5 is a bottom perspective, exploded view of the needle cap safetyassembly;

FIG. 6 is a sectional view through the clip ring and a detail excerpt ofits wall with a locking tab;

FIG. 7 is a sectional view of the receiver of the assembly, without thehypodermic needle;

FIG. 8 is a sectional view of needle cap of the assembly; and

FIG. 9 is an exploded X-ray view of the complete assembly according tothe invention, including the syringe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawing in detail and first,particularly, to FIGS. 1-3 thereof, there is seen a syringe with abarrel 1 and a piston 2. The syringe is a standard device with, say, a 3cc barrel. The syringe to be used with the invention is typically in therange from 1 to 5 cc. A distal end of the barrel 1, with reference tothe plunger handle, carries a needle cap safety assembly according tothe invention. While the needle 4 does not show in FIG. 1—i.e., it iscompletely retracted—the needle 4 is half-way exposed in FIG. 2 and itis fully extended in FIG. 3. As will be seen from the following, therelative projection of the needle 4 from the needle safety cap isachieved by sliding the needle cap back onto the barrel 1.

With reference to FIG. 4, the needle cap safety assembly 3 comprises areceiver or needle holder 5 with a standard luer lock, the needle 4, aring clip 6, and a sleeve cap 7.

With reference to FIG. 5, a luer lock 8 is integrated in the receiver 5,so that the receiver 5 with the needle 4 can be connected to a standardluer lock at the distal end of the syringe barrel 1. Two tabs 9 projectfrom the cylindrical jacket surface of the receiver 5, at diametricallyopposite points. The tabs 9 are configured to slide in tracks 10 and 11formed in the inner wall surface of the cap 7 when the receiver isinserted. The outer diameter of the receiver 5 is adapted to the innerdiameter of the cap 7 so as to assure good slidability, yet an otherwiserigid fit to provide for a relatively stable connection. In a preferredembodiment of the invention, the outer diameter of the receiver is0.540″ and the inner diameter of the cap 7 is 0.555″ in one directionand 0.580 in a perpendicular direction. That is, one of the two jackets(inner surface of the cap 7 or outer jacket surface of the receiver 5)may be formed slightly unround or elliptical. This aids in thefunctionality of the devices and provides for a better functional lockbetween the two components.

The ring clip 6 is also formed with several tabs 12. The tabs 12 projectfrom the inner wall surface and are configured to lock intocorresponding openings 13 formed in the cap 7. The tabs 12 and theopenings 13 (through holes or blind bores) are formed so that the easilysnap into one another during the assembly of the device, yet do noteasily come apart during use. In a preferred embodiment, as illustratedin FIG. 6, the tab 12 is formed with a draft angle of approximately 30°to enable insertion and snapping into the opening 13. The backside ofthe tab 12, i.e., the side facing the plunger handle of the syringe, isformed with a 90° angle. This ensures proper locking of the snap ring onthe cap 7.

In the alternative, or in addition, any of several attachment processesare possible. For example, the ring clip 6 may be glued to the cap 7 orwelded by common vulcanization or with ultrasonic welding. Any or all ofthese options may be chosen, in any combination.

With reference to FIG. 7, the receiver 7 has a conical stub 13 intowhich a base of a needle is inserted and locked. The conicity of theinner surface of the stub 13 may be defined by a draft angle ofapproximately 3°, thus assuring proper hold for the needle base. Theoutside of the needle base is conventionally formed with a thread ridgeor a tread tab so as to enable it to be threaded into the standard luerlock tread at the distal end of the syringe. The receiver and the needlebase, as well as the needle itself, may be integrally formed, with theneedle directly integrated into the mold of the receiver. Alternatively,the needle may be inserted and glued into the receiver after its releasefrom the mold.

With reference to FIG. 8, the cap 7 is formed with the twoabove-mentioned sliding tracks 10 and 11, as well as a locking track 14.The locking track 14 sets the full extension of the cap 7 and thus hidesthe needle 4 inside the cap 7. The track 10 allows half-way extension,i.e., a “short” needle will emerge from the tip 15 of the cap 7. Thetrack 11 allows the cap 7 to be slid back onto the barrel to is fullextent, i.e., a “long” needle will emerge from the tip 15. The shortneedle setting may be used, for example, for drawing medication, forshallow muscle injections or for petite persons. The long needle settingwould typically be used for deep muscular injection.

The receiver 5 is prevented from sliding backwards, out of the cap 7beyond its locked position in the track 14 by a backwall 16 of the clipring 6. As the receiver 5 slides forward inside the cap 7, the needletip emerges from the tip 15. A needle guide 17 is provided for thatpurpose. The needle guide 17 has a conical entry segment followed by acylindrical stabilization segment. The latter has a diametercorresponding to the largest rated needle diameter. The top of the capis formed with a membrane 18, which may be a simple plastic foil or aspun-on plastic that ruptures as the needle emerges from the tip. Themembrane 18 assures that the needle is completely encased and protectedfrom contamination during shipping and storage prior to use. If thedevice is used for multiple injections, as the needle is retracted, themembrane closes and once more protects the needle against contaminationduring the interim periods.

With reference to FIG. 8, there is illustrated an exploded X-ray view ofthe complete assembly, including the syringe. As shown, the needle base19 has a thread ridge 20 the meshes with an inner thread 21 at thedistal end of the syringe. The luer lock stem 22 is configured to lockinto the base 19. The distal end of the syringe with the luer lock,generally identified with numeral 23, slides into the receiver 5. Asshown inside the cap 7, the tracks 10 and 11 are multiplied.

It is possible to use the new syringe and needle cap assembly withoutopenly exposing the needle 4. For example, if medication is to bewithdrawn from a container to fill the barrel, the tip 15 is placed ontothe container, with the membrane 18 aligned with the membrane of themedication container. The cap 7 is then rotated so as to move the tab ortabs 9 from the locking track 14 into alignment with the sliding track10 or 11. Since only a short needle is necessary for the withdrawaloperation, the alignment with the track 10 is sufficient. The tip 15remains in contact with the top of the container. After filling thebarrel to the desired level, the cap 7 is pushed forward while thesyringe and the needle are being retracted. As the needle pulls out ofthe container, it also retracts beyond the membrane 18 and into the cap7. Similarly, if an injection is be administered, the tip 5 of the cap 7is placed onto the skin, the needle is then driven out to the desiredlength—and at the same time driven into the patient's tissue—all thewhile with the tip remaining in contact with the skin. During thewithdrawal of the needle, once more, the tip 15 remains in contact withthe skin, until the needle is hidden inside the cap 7.

The various rotational positions may be adapted to the specific use ofthe device. For instance, in the preferred embodiment, the lockingposition and the sliding positions (tracks 10, 11) are set so that, whenthe cap protector assembly is unscrewed from the syringe, the assemblyis automatically set to the locking position with the needle completelyretracted inside the inner space. This provides for a sharps protectorwith added safety.

Also, the inside of the cap 7 is formed with a draft angle such that,when the receiver 5 is fully pushed forward (the needle 4 is completelyextended), the receiver 5 is friction locked in the cap 7. This makesfor a very stable assembly during its use.

The advantages of the novel device are immediately apparent. By way ofexample, the device provides for safe medication withdrawal with aclearly reduced likelihood of a needle-stick injury. Safe and sterilemedication storage is assured until the timing of the actual injectionand between partial injections, because the safety cap completelyencloses the sharps element. The full enclosure also assures safetransportation to the patient or laboratory. The injection can beeffected without ever exposing the needle to the patient. The device canreplicate two or more needle sizes for a variety of injection depths.Finally, the device can be locked and thus protected against accidentalsharps injury following the injection.

The novel device is suitable for a variety of applications. Forinstance, all intramuscular injections can be performed, as well as allI.V. injections, and lidocaine injections. Finally, as noted above, thedevice is well suited for medication withdrawal.

1. A protective cap assembly for a sharps device, comprising: a receiverfor rigidly holding a sharps element of the sharps device; a protectivecap assembly attached to said receiver and completely encasing thesharps element in a closed position of the cap assembly; said receiverbeing movably disposed in said protective cap assembly, for movementfrom the closed position to a functional position in which the sharpselement projects from said protective cap assembly and the sharps deviceis in a functional condition, and from the functional position to theclosed position in which the sharps element is completely retracted insaid protective cap assembly.
 2. The assembly according to claim 1,wherein said protective cap assembly includes a clip ring and aprotective cap attached to said clip ring, and wherein said clip ring isconfigured to limit a movement of said receiver in one direction andsaid cap is configured to limit the movement of said receiver in anotherdirection.
 3. The assembly according to claim 2, wherein said receiverhas a tab formed on a substantially cylindrical jacket surface thereof,and said protective cap assembly is formed with at least one groove inan inner jacket surface thereof, defining a track within which said tabslides from the locked position to the functional position.
 4. Theassembly according to claim 1, wherein the sharps device is a syringeand the sharps element is a hypodermic needle.
 5. A needle cap assemblyfor a syringe having a distal end and a hypodermic needle projectingfrom the distal end, the needle cap assembly comprising: a receiverrigidly mountable at the distal end and rigidly holding the hypodermicneedle; a protective cap mounted on said receiver and slidable relativeto said receiver between a closed position in which the protective capencases the hypodermic needle completely and a functional position inwhich the hypodermic needle projects out of said protective cap; andmutually cooperating locking devices on said protective cap and on saidreceiver for locking said protective cap in the closed position.
 6. Theneedle cap assembly according to claim 5, wherein said protective caphas a tip formed with an opening through which the needle projects inthe functional position, and a membrane covering and substantiallysealing said opening when the protective cap is in the closed positionand the needle is completely retracted inside said cap.
 7. The needlecap assembly according to claim 5, which comprises a clip ring connectedwith said protective cap, and wherein said clip ring is configured tolimit a movement of said receiver in one direction and said protectivecap is configured to limit the movement of said receiver in anotherdirection.
 8. The needle cap assembly according to claim 7, wherein saidreceiver has a tab formed on a substantially cylindrical jacket surfacethereof, and said protective cap is formed with at least one groove inan inner jacket surface thereof, defining a track within which said tabslides from the locked position to the functional position.
 9. A syringeassembly, comprising a syringe having a plunger and a barrel with adistal end, the needle cap assembly according to claim 5, a needle heldin said receiver and mounted, together with said receiver and saidneedle cap assembly, to said distal end of said barrel.
 10. The syringeassembly according to claim 9, wherein said distal end of said barrel isformed with a luer lock and said needle cap assembly and said needletogether are formed to be mounted on said luer lock.